Glaciers and ice fields on the west coast of Spitsbergen, Svalbard, Norway

PHOTO: OBERTHARDING/ALAMY STOCK PHOTO

Although seemingly inhospitable, glaciers host a range of microbial activities. Algal blooms are common on the surfaces of snow and ice, for example, which can lower albedo and increase melting. Lutz et al. identified the algal communities, along with archaea and bacteria, on 12 glaciers and permanent snowfields in Norway and Sweden. Correlations between nutrient ratios and metabolite production point to commonalities in community function between sites. The synthesis of some darkening carotenoid compounds, for example, is critically dependent on the availability of nitrogen. If atmospheric nitrogen deposition increases as expected, more frequent algal blooms may lead to more glacial melting.